Associate Professor Ceridwen Fraser.
Winter warming is often overlooked when considering the impacts of climate change and researchers have turned to social media-inspired models to address this gap in scientific knowledge.
University of Otago researcher Associate Professor Ceridwen Fraser was part of an international team that used network modelling to identify the significant impacts of warming seas on the world’s fisheries.
The research, published in the prestigious journal Nature Climate Change, assembled a holistic picture of the impact of warming on fish stocks in the Mediterranean Sea, a biodiversity hotspot which is under threat from rapidly warming seas.
Department of Marine Science Associate Professor Fraser says a great deal of research and media attention has been on the impacts of extreme summer temperatures on people and nature, but the startling result from this study was the impact of winter warming.
“Interestingly, coastal water temperatures are expected to increase at a faster rate in winter than in summer and this research shows that warmer winters could also lead to ecosystem disruption, in some cases more than summer warming will.
“Our results suggest that winter warming will cause fish species to hang out together in different ways, and some species will disappear from some areas entirely.”
Ecosystem models often only focus on the effects of the environment, but models incorporating interactions between species – similar to how social media algorithms work – can give better insights into how ecosystems will change.
Lead researcher Dr Nick Clark from The University of Queensland says the use of newer models that are commonly used in social media to document people’s social interactions, offer an exciting way to address this gap in scientific knowledge.
“These innovative network models give us a more accurate picture of reality by incorporating biology, allowing us to ask how one species responds to both environmental change and to the presence of other species, including humans,” Dr Clark says. The study used information from decades of research describing the geographical ranges of more than 600 Mediterranean fish species. This information was incorporated into a network model along with data from the Intergovernmental Panel on Climate Change’s climate projections.
Dr Clark says the network model highlighted the widespread effects on fish biodiversity of warming water temperatures, particularly in winter.
“If fish communities are more strongly regulated by winter temperatures as our model suggests, this means that fish diversity may change more drastically and rapidly than we previously thought,” Dr Clark says.
“For the sake of marine ecosystems and the people whose livelihoods depend on them, we need to gain a better understanding of how ocean warming will influence both species and economies.”
Associate Professor Fraser says while this study focussed on the Mediterranean due to the long-term data available for that region, the results almost certainly also apply to other coastal marine ecosystems around the world.
“These cutting-edge modelling approaches provide exciting new tools for us to use data from yesterday and today to understand what will happen in marine ecosystems tomorrow.”
Link to paper:
The research has been published in Nature Climate Change (DOI: 10.1038/s41558-020-0838-5) and included contributions from James Cook University’s Dr James Kerry.